This invention pertains to improvements in a chamber that is coupled to the end of a heat exchanger tube and is adapted to capture a brush which is propelled back and forth through a tube that is to be cleaned under the influence of fluid whose flow direction is reversible. Chambers having some of the features exclusive of the improvements described herein are shown and described in U.S. Pat. No. 3,319,710 dated May 16, 1967.
A common type of heat exchanger in which the new cleaning element capturing chambers may be used has a bundle of tubes fixed at opposite ends in headers. Typically, untreated cooling water flows through the interior of the tubes and exchanges heat with water or some other fluid on the outside of the tubes which is at a different temperature than the water flowing on the inside of the tubes. As is well known, if the water flowing through the tubes is untreated or inadequately treated for minimizing precipitation of minerals, a mineral deposit will gradually accumulate on the inside of the tubes. As taught in the cited patent, accumulation of mineral in the tubes can be inhibited by propelling a brush or other cleaning element through the tubes periodically to dislodge the mineral so it may be entrained in cooling fluid and carried away. The brush capturing devices are attached to the ends of the tubes. Heretofore, brush capturing chambers have been molded out of synthetic resin. The chambers have an integral tubular portion for being inserted in the end of a tube or in a coaxial hole in the header. The chambers are usually bonded or otherwise fastened in their receiving holes in such manner that any attempt to remove them results in their destruction. The brush or other cleaning element, of course, is placed in the chamber before it is inserted in its receiving hole. Occasions arise, however, when it is desirable to have clear access to the interior of the heat exchanger tubes such as for the purposes of replacing worn cleaning elements or admitting a probe for testing the integrity of the tube walls. Heretofore, the only way that this could be done was to break the chamber away and replace it with a new one when the test was completed.